Regression in Left Ventricular Hypertrophy and Fibrosis in Aortic Stenosis

Inclusion Criteria: * Participants ≥ 18 years * Left Ventricular Ejection Fraction (LVEF) ≥40%. * Diagnosed with severe symptomatic aortic stenosis\* by a cardiologist or cardiac surgeon. o Severity of AS follows international guideline criteria \[38\], namely at least one out of: effective orifice area \[EOA\] \<1.0 cm2, indexed EOA of ≤0.6 cm2/m2, peak velocity ≥4.0 m/s or mean gradient \>40 mmHg. \* including severe low flow low gradient AS * Referred for surgical or transcatheter AVR (SAVR or TAVI). * Able to provide informed consent and comply with study procedures. Exclusion Criteria: * Current use or intolerance or hypersensitivity to MRAs or SGLT2-inhibitors. * Hyperkalaemia (K\>4.5 mmol/L) * Significant renal impairment (eGFR \< 45 mL/min/1.73m²) * Severe hepatic insufficiency * Concomitant severe other valve lesion (severe MR, MS or AR) * Contraindications to MRAs including: * Addison's disease. * Acute porphyrias. * Receiving potassium-sparing diuretics, potassium supplements or strong inhibitors of CYP 3A4 (for example. itraconazole, ketoconazole, ritonavir, nelfinavir, clarithromycin, telithromycin and nefazodone). * Contraindications to SGLT2-inhibitors including: * Active urinary tract infections. * At risk or with a history of diabetic ketoacidosis * Type 1 or Type 2 Diabetes on insulin. * Concomitant diagnosis affecting trial participation or life expectancy of less than two years as evaluated by the treating clinician. * Contraindications to MRI (e.g. non-conditional cardiac pacemaker, severe claustrophobia, inability to lie flat: participants who do not meet local safety rules for MRI). NB: Conditional pacemakers/ICDs, if implanted after the baseline scan, are not an exclusion, depending on local expertise. * Ongoing participation in another CTIMP interventional clinical trial (i.e. drug trial), will not be permitted. Participation in any other trial will need to be discussed with the trial investigators. * Significant comorbidities that would contraindicate participation, including uncontrolled hypertension, or recent myocardial infarction (within 3 months prior to screening). * Pregnancy or breastfeeding, or females of childbearing potential not using an effective method of contraception. * Any other medical or psychiatric condition that would interfere with participation or compliance with study procedures as determined by the Principal Investigator (PI). * As evidenced by features of decompensated cirrhosis e.g. hepatic encephalopathy, ascites, jaundice or markedly deranged liver blood tests e.g. elevated bilirubin, serum albumin \<30 or deranged clotting